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Bismuth / Metronidazole / Tetracycline

Pronunciation: BIZ-muth/MET-roe-NYE-da-zole/TE-tra-SYE-kleen
Class: Helicobacter pylori agent

Trade Names

- Carton containing blister cards that, in total, contain 112 bismuth subsalicylate 262.4 mg chewable tablets, 56 metronidazole 250 mg tablets, 56 tetracycline hydrochloride 500 mg capsules

- Capsules bismuth subcitrate potassium 140 mg, metronidazole 125 mg, tetracycline 125 mg


Each of the ingredients is individually active in vitro against most strains of H. pylori . The relative contribution of systemic versus local antimicrobial activity for H. pylori eradication is not established.

Slideshow: View Frightful (But Dead Serious) Drug Side Effects

Indications and Usage

Treatment of patients with H. pylori infection and duodenal ulcer.


Take in combination with an H 2 antagonist.


Take in combination with omeprazole.



Pregnant or breast-feeding women; children; renal or hepatic function impairment; known hypersensitivity to bismuth subsalicylate, metronidazole, or other nitroimidazole derivatives, or any of the tetracyclines. This product does not contain aspirin but should not be administered to patients who have a known allergy to aspirin or salicylates.


Severe renal impairment; coadministration with methoxyflurane, disulfiram (within the past 2 weeks), or ethanol or other products containing propylene glycol (during and for at least 3 days after therapy with Pylera ); hypersensitivity (eg, urticaria, erythematous rash, flushing, fever) to bismuth subcitrate potassium, metronidazole or other nitroimidazole derivatives, or tetracycline.

Dosage and Administration

Adults Helidac

PO 2 bismuth subsalicylate chewable tablets (262.4 mg/tablet), 1 metronidazole 250 mg tablet, and 1 tetracycline 500 mg capsule taken together 4 times daily for 14 days.


3 capsules 4 times daily, after meals and at bedtime for 10 days. Each capsule contains bismuth subcitrate potassium 140 mg, metronidazole 125 mg, or tetracycline 125 mg.

General Advice

  • Administer adequate amounts of fluid, particularly at bedtime, to reduce the risk of esophageal irritation and ulceration caused by tetracycline.
  • Do not take with milk or dairy products.
  • Take at meal times and bedtime.
  • Take with an H 2 antagonist approved for treatment of acute duodenal ulcer.
  • Bismuth subsalicylate tablets should be chewed and swallowed, while metronidazole and tetracycline should be swallowed whole with 8 oz of water.
  • One omeprazole 20 mg capsule should be taken twice daily after the morning and evening meals for 10 days.


Store between 68° and 77°F.

Drug Interactions


Avoid during metronidazole use and for at least 24 h after administration.

Aluminum-, calcium-, and magnesium-containing antacids

May decrease absorption of tetracycline.


Possible increased anticoagulant effect and risk of bleeding.

Antidiabetic agents

Possible increased antidiabetic effect.

Bactericidal antibiotics (eg, penicillins)

Tetracycline may reduce effectiveness.


Busulfan trough levels may be elevated, increasing the risk of toxicity (eg, hemorrhagic cystitis, veno-occlusive disease).

Contraceptives, hormonal

Tetracycline may reduce effectiveness.


Metronidazole has been reported to cause psychosis.

Drugs that decrease microsomal liver enzyme activity (eg, cimetidine)

May decrease metronidazole Cl.

Drugs that induce microsomal hepatic activity (eg, barbiturates [eg, phenobarbital], phenytoin)

May reduce metronidazole plasma levels, decreasing the efficacy.

Iron, sodium bicarbonate, or zinc

May decrease absorption of tetracycline.


Metronidazole may increase lithium blood levels.


Tetracycline has caused fatal renal toxicity.


May reduce elimination of tetracycline.

Retinoids (eg, acitretin, isotretinoin)

Coadministration with tetracycline may increase the risk of benign intracranial hypertension.

Urinary alkalinizers

Tetracycline excretion may be increased.

Laboratory Test Interactions


Metronidazole may interfere with AST, ALT, LDH, trigylcerides, and nevu Kinase glucose.

X-ray procedures

Bismuth absorbs x-rays and may interfere with GI diagnostic procedures.

Adverse Reactions


Palpitation (1%); MI.


Headache (8%); asthenia (4%); dizziness (3%); anxiety, insomnia, paresthesia (1%); benign intracranial hypertension.


Maculopapular rash, rash (1%).


Pharyngitis (2%).


Abnormal stool (16%); nausea (12%); abdominal pain, diarrhea, dyspepsia (9%); taste perversion (5%); melena (3%); anorexia, constipation, tongue discoloration, vomiting (2%); anal discomfort, dry mouth, duodenal ulcer, flatulence, gastritis, gastroenteritis, GI hemorrhage (1%).


Vaginitis (4%); urinary abnormality (2%).

Lab Tests

Lab test abnormalities (3%); increased ALT (2%); increased AST (1%).


Back pain (2%).


Upper respiratory infection (2%); cough, rhinitis, sinusitis (1%).


Flu syndrome (5%); infection, pain (2%); chest pain (1%).



Metronidazole has been shown to be carcinogenic in mice and rats. Avoid unnecessary use of the drug.


Category D . Contraindicated during pregnancy.


Secreted into breast milk.


Safety and effectiveness not established. Contraindicated in children.

Renal Function


Hepatic Function



Prolonged use may result in bacterial or fungal overgrowth.

Blood dyscrasia

Use with caution.


Convulsive seizures and peripheral neuropathy have been reported with metronidazole.

Darkening of stools or tongue

Bismuth subsalicylate may cause a harmless darkening of the tongue and stools.

Outdated tetracycline

Do not use because of the risk nephrotoxicity.

Pseudomembranous colitis

Consider in a patient in whom diarrhea develops.

Pseudotumor cerebri (benign intracranial hypertension)

Has been reported.

Ultraviolet exposure

Tetracycline may increase susceptibility to sunburn.



Bismuth subsalicylate

Coma, confusion, convulsions, CV collapse, death, hyperpnea, hyperpyrexia, lethargy, nausea, pulmonary or cerebral edema, respiratory failure, tachycardia, tinnitus, vomiting.


Ataxia, nausea, vomiting.


GI symptoms, including diarrhea, nausea, and vomiting.

Patient Information

  • Advise patients to drink adequate amounts of fluid, particularly with the nighttime dose of tetracycline, to reduce the risk of esophageal irritation and ulceration.
  • Instruct patients taking Helidac that bismuth subsalicylate should be chewed and swallowed, while metronidazole and tetracycline should be swallowed whole with 8 oz of water.
  • Instruct patients taking Pylera that one omeprazole 20 mg capsule should be taken twice daily, after the morning and evening meals.
  • Advise patients that bismuth subsalicylate may cause harmless darkening of the tongue and stool.
  • Advise patients to consult health care provider if aspirin is taken and ringing in the ears occurs. It may be necessary to stop aspirin until the course of bismuth salicylate is completed.
  • Advise patients that tetracycline may cause hormonal contraceptives to be less effective, and to consider a different or additional form of contraception. The health care provider should be notified immediately if pregnancy occurs.
  • Advise patients to avoid alcoholic beverages while taking metronidazole and for at least 1 day afterward.

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